Just before Halloween, it’s time for tricks and treats about monsters in the fossil record. Here’s a list of recent stories about scary beasts:
- Dino Dance: Are these potholes tracks or weathering marks? PhysOrg and Science Daily were among news outlets reporting a new interpretation of formations by a grad student at the University of Utah in Navajo Sandstone near a popular photographer’s locale called The Wave. Winston Seiler claims the round holes represent tracks of three different kinds of dinosaurs, complete with tail drag marks. Other dinosaur tracks are known in the area; this one is unusual for the number and density of tracks, what Seiler calls a “trample surface.” National Geographic also joined the dance party.
Update 11/10/2008: The party dispersed when some science cops showed up. PhysOrg reported that “A group of paleontologists visited the northern Arizona wilderness site nicknamed a ‘dinosaur dance floor’ and concluded there were no dinosaur tracks there, only a dense collection of unusual potholes eroded in the sandstone.” One of the co-authors of the dance floor thesis agreed to work with the skeptics: “Science is an evolving process where we seek the truth,” she said. So she turned around and changed the dance to The Shake: “This is how science works, and we’ll have to see how it shakes out in the end.”
- Hornblower: The unusual head crests on duckbill dinosaurs were used for shouting, claim scientists in a report on Live Science and PhysOrg. The nasal passages on lambeosaurs and corythosaurs connected with passages in the head crest to produce resonant, bellowing calls (see diagrams on Science Daily). The pitch of the calls probably deepened as the dinosaurs aged. Perhaps they had a tonal language for communication, with special calls for Run for your lives! A T. rex is coming! Veteran dinosaur hunter Jack Horner (Montana State) noted that, “It’s difficult to infer the function of structures in an extinct dinosaur when there is so little resemblance to any living animal.”
- Taking the plunge: How do you interpret dinosaur tracks that gradually fade away? The track-maker must have gone for a swim, reported Science Daily. Debra Mickelson of University of Colorado even thinks she knows what they were doing – going out to sea to feed, 165 million years ago.
- Migrants: Dinosaurs weren’t the champion migrators of the ancient world, contrary to the usual view, said Phil Bell (U of Alberta) in a report on Science Daily. How could he and colleague Eric Snively figure that out? They calculated the energy requirements for a herd of herbivores like Edmontosaurs, and believe it would have limited their travel to 3000 km round trip – half the previous estimate.
- Microsaur: We tend to think of dinosaurs as mighty tyrants of the early earth, making the ground shake with every step. Science Daily reported the finding of the smallest dinosaur ever seen. The juvenile Heterodontosaurus (mixed teeth) had a skull less than two inches long and would have weighed less than two sticks of butter. “It’s likely that all dinosaurs evolved from carnivorous ancestors,” said co-author Laura Porro (U of Chicago); “Since heterodontosaurs are among the earliest dinosaurs adapted to eating plants, they may represent a transition phase between meat-eating ancestors and more sophisticated, fully-herbivorous descendents.”
- Megasaur: A dinosaur graveyard has been found in Utah, reported Live Science. Remains of a large number of herbivores were found, including one well-preserved skeleton and a 5-foot humerus from a brachiosaur, one of the largest dinosaurs known. Tracks have also been found. Another surprise was a Deltapodus stegosaur – previously known only from Europe. How did brachiosaurs get so huge? Another story on Live Science claims they ate high-energy foods whole, without chewing.
- Sniffer rex: Halloween wouldn’t be quite the same without mention of everyone’s favorite dinosaur nightmare: the Tyrannosaurus rex. A report on Live Science claims the monsters had a good sense of smell – vital for hunting down prey. They believe this based on the size of the opening in the skull where the olfactory bulb – an organ of smell – was located. The article speculated on evolution of birds from dinosaurs: “Most of today’s birds have keen eyesight but lack a good nose, suggesting smell became less important at some point in birds’ ancestral history, the researchers said.”
It’s clear that dinosaur hunting is still a popular sport for paleontologists, especially ones with vivid imaginations.
Dinosaurs are for kids – including the grown-up kind. Who doesn’t enjoy learning about this large and varied class of extinct animals that roamed the whole earth? Imagining things is fun, too. Just don’t confuse it with science. There are limits to how much can be known about dinosaurs from their tracks and bones. We don’t know, for instance, their favorite dance steps, to say nothing of how they decided to give up meat, reduce their noses and fly like Tweety rex. The beasts are scary enough without the evolutionary monster tales around the campfire.